The overall goals of this longitudinal study are to examine etiologic predictors and consequences of women's tobacco use and dependence in late midlife. Our focus related to the late midlife experience will be on the broader socioenvironmental context (e.g., neighborhood services and organizations, neighborhood cohesion, social network, and social support), in interaction with individual factors related to tobacco use and dependence, drug use, health, and psychopathology. The original sample in 1975 consisted of women whose average age was 32 (T1). Subsequently, the women were interviewed when their average age was 40 (T2), 42 (T3), and 47 (T4). A fifth data collection (T5) for the women is proposed when the participants are an average age of 62, in order to accomplish the following: (1) examine interrelations and interactions of personality (including psychopathology), family, friend, and socioenvironmental contextual factors as they relate to the course of tobacco use and dependence over time (i.e., stability and change) and cessation;(2) study the consequences of long-term tobacco use and dependence on women's psychopathology and functioning;and (3) examine the impact of tobacco dependence and cessation across two generations. Interviews will be conducted in the participants'homes by trained interviewers. Scales with adequate psychometric properties measuring the independent variables will be developed. The primary analytic techniques will be causal analysis, logistic regression analysis, and growth mixture modeling. The significance of this study for public health lies in the intrapersonal, interpersonal, and neighborhood longitudinal data available at several crucial stages of development. Since tobacco use is a major predictor of many adverse health outcomes in women (e.g., cancer), this study will have great relevance for the mission of the National Cancer Institute. Knowledge of the longitudinal pathways to tobacco dependence from age 32 to 62 and the cessation of tobacco use will help provide detailed and specific guidelines for treatment. This study is also unique in that the long-term effects of tobacco use and dependence can be evaluated for their cumulative impact. In addition, by identifying protective factors that can mitigate the adverse effects of tobacco use and dependence on women's functioning in late midlife, we can provide additional information necessary for effective treatment efforts and public policy.